| OL | 1983 | ||||
| OL(P) | 1993 | United States | object-oriented extension to Prolog | ||
| OL/2 | 1973 | United States | |||
| OLABL | 1995 | France | |||
| OLC | 1966 | On-Line | Arithmetic | United States | UCSB students |
| OLDAS | 1968 | Expression oriented | United States | ||
| OLGA | 1985 | France | Language for specification of attribute grammars | ||
| OLI | 1997 | ||||
| OLIVER | 0 | ||||
| Ollongren | 1979 | ||||
| OLM-1 | 1977 | Japan | |||
| olog | 1997 | Canada | |||
| OLQ2 | 0 | Business Data Processing | Hierarchical DB | United States | IDMS query language |